from io import BytesIO
import matplotlib as mpl
from matplotlib import pyplot as plt
from matplotlib.patches import PathPatch
from matplotlib.path import Path
import numpy as np

mpl.use("qtagg")
mpl.rcParams["path.snap"] = True  # Default, set to False to remove the problem.

fig = plt.figure(figsize=(6, 2), dpi=200)
ax = fig.add_subplot()
# Define a path with three connected components; the last one has slanted parts.
xys = [
    [0.0, 4.5],
    [0.740033943422379, 4.5],
    [1.259966056577621, 4.5],
    [1.774087425970262, 4.5],
    [2.2259125740297376, 4.5],
    [3.0, 4.5],
    [4.0, 4.5],
    [4.5, 4.0],
    [4.5, 3.0],
    [4.5, 2.0],
    [4.5, 1.0],
    [4.5, 0.0],
]
M = Path.MOVETO; L = Path.LINETO
codes = [M, L, M, L, M, L, L, L, L, L, L, L]

# Draw as single Path, save as png.
ax.clear(); ax.set(xlim=(0, 9), ylim=(0, 9)); ax.set_axis_off()
ax.add_artist(PathPatch(Path(xys, codes), facecolor="none"))
buf0 = BytesIO(); fig.savefig(buf0, format="png"); buf0.seek(0)

# Draw as multiple separate Paths, save as png.
ax.clear(); ax.set(xlim=(0, 9), ylim=(0, 9)); ax.set_axis_off()
for sl in [slice(0, 2), slice(2, 4), slice(4, 12)]:
    # One can also explicitly pass the codes (Path(xys[sl], codes[sl])); this makes no
    # difference with leaving the codes as None.
    ax.add_artist(PathPatch(Path(xys[sl]), facecolor="none"))
buf1 = BytesIO(); fig.savefig(buf1, format="png"); buf1.seek(0)

plt.close("all")

# Summarize the results.
im0 = plt.imread(buf0)[..., 0]  # monochrome, so we can just take one channel.
im1 = plt.imread(buf1)[..., 0]
axs = plt.figure(figsize=(8, 8), layout="constrained").subplots(3, sharex=True, sharey=True)
axs[0].imshow(im0, cmap="gray")
axs[1].imshow(im1, cmap="gray")
axs[2].imshow(im0 - im1, cmap="bwr", clim=(-1, 1))
axs[2].set(title=f"diff image; max={abs(im0 - im1).max():.4f}")

plt.show()